The invention involves a radially expandable support structure (e.g., a stent, graft or prosthesis) for holding open and/or expanding lumina within a body, especially in a blood vessel. The structure includes a tube-shaped body having a wall surface extending between a first and a second end which is formed from elongate members connected to each other, having a first group of members which extend essentially in the longitudinal direction of the tube-shaped body, wherein respectively adjacent members of this first group are connected in pairs to each other at their ends to form a member pair which encloses a slit or opening, wherein these member pairs are connected approximately in the middle of their longitudinal extension to member pairs arranged adjacent to each other in the circumferential direction of the tube-shaped body to form a ring around the longitudinal axis of the tube-shaped body, and wherein several rings connected to each other at the ends of the slits are arranged along the longitudinal axis of the tube-shaped body.
Support structures of this type are known, for example from European patent EP 335 341 B1. Support structures are described therein which are formed from elongate member pairs. These support structures are inserted into narrowed blood vessels or into other body passages having a lumen, in order to keep them open after expanding them by balloon dilatation. In this process, the support structures are expanded in their diameter and become shortened during expansion. This type of shortening is generally not desirable, however, since this shortening necessitates that a considerably longer support structure than is immediately required at the application site must be inserted into the body opening. The known structures adapt to the bends or curves in the body openings relatively poorly or not at all, so that additional bending components must be provided (EP 335 341 B1). The known support structures have rigid, tube-shaped sections which are connected flexibly to each other by hinged connections. In practice, it has generally been shown that tissue hypertrophy can occur in these hinged areas, caused by continuous agitation in the tissue seating area.
Other known structures exhibit pronounced shortening during expansion. Spiral structures are also known. These exhibit at their ends behavior unsuitable for insertion.